try for cleaner terminal prompt (merge from devbr6)

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@40670 15284696-431f-4ddb-bdfa-cd5b030d7da7

mswindows/GRASS-Installer.nsi

@@ -647,6 +647,8 @@ Section "GRASS" SecGRASS
 	FileWrite $0 'GRASS_PROJSHARE="$INSTALL_DIR\proj"$\r$\n'
 	FileWrite $0 'export GRASS_PROJSHARE$\r$\n'
 	FileWrite $0 '$\r$\n'
+	FileWrite $0 'export PS1="GRASS 7> "$\r$\n'
+	FileWrite $0 '$\r$\n'
 	FileWrite $0 'exec "$$GISBASE/etc/Init.sh" "$$@"'
 	FileClose $0
 	done_create_grass_command: